Background and Objective: The issue of marital infidelity in Iranian society is a growing concern which is accompanied to unsustainable relationships and high divorce rates. The present study aimed to study the psychometric properties of the Persian version of marital infidelity questionnaire. Materials and Methods: This is a descriptive-psychometric research in which 400 university students of AzarbaiijanShahidMadani University were selected by stratified random sampling method and were studied. The data were analyzed using a confirmatory and exploratory factor analysis (analysis of main components with varimax rotation), multivariate analysis of variance. Results: analysis of factors were performed using the internal consistency method as well as re-test for the reliability of the present questionnaire. For validity, a confirmatory factor analysis was used, results suggested consistent and accurate relationship between the components of this questionnaire. The internal consistency of questionnaires by Cronbach's alpha for the components including legitimacy, seduction, normalization, sexual orientation, social context, and excitement were 0. 79, 0. 75, 0. 54, 0. 79, 0. 71, 0. 79 respectively and for the whole questionnaire was0. 91. The reliability was calculated obtained by two-half method for all scales as 0. 81(r=0. 81) Conclusion: In sum, the results of the research confirmed validity of the Persian form of the Marital Infidelity Questionnaire, which indicates that Marital Infidelity Questionnaire is a reliable and valid instrument as well as it can be used in clinical and research setting. Therefore, the current questionnaire has an appropriate reliability and validity for using by researchers and specialists.